OBD Guide

P0451

EVAP System Pressure Sensor/Switch A Circuit Range/Performance

P0451 is an OBD-II diagnostic trouble code meaning: EVAP System Pressure Sensor/Switch A Circuit Range/Performance. Common causes: evap system pressure sensor malfunction, open or short circuit in wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Check Engine Light Is On
  • Increased fuel consumption
  • Smell of gasoline in the cabin

Causes

  • EVAP system pressure sensor malfunction
  • Open or short circuit in wiring harness
  • Problems with the engine control unit
  • Clogged or damaged EVAP system lines

How to Fix

  1. Check the integrity of the sensor wiring harness
  2. Check the resistance and voltage of the pressure sensor
  3. Clean or replace pressure sensor
  4. Check the EVAP system for leaks

Related codes

Error P0451 by Vehicle Brand

FAQ

What does the P0451 code mean?

P0451 is an OBD-II diagnostic trouble code that indicates: EVAP System Pressure Sensor/Switch A Circuit Range/Performance

What causes a P0451 error code?

The most common causes of P0451 include: EVAP system pressure sensor malfunction; Open or short circuit in wiring harness; Problems with the engine control unit; Clogged or damaged EVAP system lines.

How do I fix a P0451 diagnostic trouble code?

To fix P0451: Check the integrity of the sensor wiring harness. Check the resistance and voltage of the pressure sensor. Clean or replace pressure sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0451?

Limited driving only, diagnose soon

How much does it cost to fix P0451?

The estimated repair cost for P0451 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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